Fig. 2.

Temporal regulators of cell fate specification.

A) Schematic of the temporal birth windows of retinal cell types from the common multipotent retinal progenitor cell (RPC), highlighting the stereotyped, but overlapping birth order of retinal neurons and glia. B) Heatmap indicating the normalized expression (znorm) of ‘classic’ competence factors — Pou2f1 and Casz1 — and the new retinal competence factor — Foxn4 — within mouse RPCs across scRNA-seq experiments (Clark et al., 2019). Pou2f1 is expressed within early retinal development, followed by expression of Foxn4. Casz1 expression is consistent with the temporal windows in which rod photoreceptors are specified. C-D) Heatmaps indicating the normalized expression (znorm) of temporal neuronal fate regulators (Sagner et al., 2020) across RPCs of the C) developing mouse, and D) developing human retina (Clark et al., 2019; Lu et al., 2020), indicating temporally restricted expression patterns within early (Onecut1/2, Zfhx3/4, Pou2f2) and late (Nfib/Nfia) periods of retinal development.